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I'm sure I'm not the first to point this out. But the prominent "rated range" indication (as opposed to "projected range") is misleading to people who don't understand what it means - and I think that's most potential buyers. Its needlessly optimistic and leaves inexperienced or non-math savvy drivers open to mistakes. It also hurts with reviewers.

They should list how much charge is in the battery, and what the projected range is, and leave it at that - just like a regular car. A regular ICE car tells you how much fuel you have left and the projected range - which you know is an educated guess - and lets you figure it out yourself from there. It's intuitive and its the way every ICE car in the world does it.

Right? Am I missing something here?

David Trushin | February 15, 2013

I wouldn't mind if that were removed fromt he main display. But it would be nice if we could cycle through a few parameters on the instrument panel, like
kWh used since last charge (I can live with the battery bar)
estimated miles remaining
average (choose your favorite:Wh/m, m/Wh, m/kWh)
Instantaneous (same choices)
average speed
These are the same (except for obvious differences) that I get on my ICE. Normally I use the miles remaining indicator to plan my refueling stop. With my ICE I use it to figure out where the cheapest gas and whether I can get there or not. I assume that some of these are going to be implemented sometime in the near future.

nickjhowe | February 15, 2013

This has been discussed elsewhere, but I think the rated range is the best of a bad set of choices. Since the S can't predict how you are going to drive, where you are going to drive, or what the weather is going to be then any estimate is flawed.

Unlike an ICE car where 1/2 a tank really is half a tank, SOC isn't really a good measure IMHO. At 70deg, 100% SOC gives 265 projected miles. At 20deg 100% SOC gives MUCH less. If a novice driver sees 100% SOC, how are they to know how much distance they might be able to do? Isn't a 'best guess' projected range estimate based on EPA rating corrected for temperature the least-bad guess?

trydesky | February 15, 2013

I've only had my car a couple weeks, but so far, I like the rated range. Instantaneous range is a fun toy (I don't want to see it go away), but it's worthless at guessing how many miles I have left. I'm sure we've all seen it swing by 100 miles in seconds.

I do like the average, but that too isn't perfect.

DTsea | February 15, 2013

I like rated range too. I feel some accomplishment when projected range exceeds rated range. It is also useful for trip planning. Gives a benchmark for driving style.

portia | February 15, 2013

no, no, the projected range is way inaccurate if you were doing uphill or downhill in the last 30, 15 or 5 miles,, either too low or too high, the rated range is better and more useful.
I have seen my projected range at 999 miles, it is fun to look at but completely useless indicator of how far I might be able to drive.

jat | February 15, 2013

I disagree -- I think rated range is a nice midway point which can easily be obtained if you want to (or better if you drive really carefully). I would personally be ok with a precise percent charge instead, but I think many people wouldn't want to do math to figure out how far they can go. As it is, if you know the way you drive uses 25% more energy than the rated range, just multiply the rated range by .8. If anything, you might allow people to enter their own Wh/mi average.

Projected is worthless because it is based on what you have driven, not what you will drive. The car can't know the future, so it doesn't know if you plant to drive 80 on the interstate or 25 on surface roads, so you are much better off just using some average and letting people adjust it in their head since they are the only ones who know how they will drive.

CnJsSigP | February 15, 2013

The new update made rated and ideal your two choices. Honestly I have been almost spot on with rated. It works out to be around 320Wh/mi.
Ideal seems optimistic to me, so this week I've been doing a maximum effort and take roads that skirt the freeway to drop the speeds to 55 vice 70. I have been able to flirt with 285Wh/mi which gets me to ideal mileage, but its not my normal drive style.
I would like to see an average of the last 500 miles or so to make a projected range to display. That way under the most common style of driving by any person, which could be anywhere between 300-400Wh/mi, it would display a realistic range for that person and their historic conditions. It would be a good slow moving average, but would change monthly and be able to react to seasonal climate changes and reflect that range. More in the summer, less in the winter.
Ideal for maximum mileage efforts, rated for typical driving, 500 mile projected for a unique range based on that person. Of course you can reference the instant from the graph to give you current real time range.

jbunn | February 15, 2013

rated is the best fit for my actual range. Projected swings wildly. I can have 80 rated left, and projected can be all over the map from 150 to 40. But what allwaysseems to happen is what I get on average is what rated said.

Koz | February 15, 2013

It should be a "smart" rated range and give highway/city rated ranges. Start using EPA values but learn the persons driving style and adjust for conditions (temp, climate control). I don't see how they can adjust for wind and that can be a big factor.

Brian H | February 15, 2013

DTsea;
+1

That's the way to use it: the benchmark if the conditions are met. As with any car or tool, experience will allow reasonable adjustments for "assumptions exceeded".

jat | February 15, 2013

@Koz - how can it learn that sometimes I drive hard and sometimes I don't?

Brian H | February 16, 2013

Average wh/mi over the last 30 mi.?

Mark Z | February 16, 2013

Rated is much better than Ideal.

The green bar clearly indicates the amount of energy left.

Using the energy application can help give estimates based on previous driving.

It's fairly easy to follow this guideline. Rated is 65 mph and Ideal is 55 mph. If you drive faster, then check your progress with the energy application.

Here is one more idea for the 85 kWh Model S. For every degree below 70, remove that many miles from the rated range with a full charge. Just an idea, but it comes close to what I have experienced and maybe others as well. Don't forget the mileage loss while parked if you aren't charging.

Maybe someone could provide a formula for driving above 65 and how that affects range. The energy application is a great help for those who like to drive fast.

stimeygee | February 16, 2013

Ok. I see I'm in the minority. I do think that average projected range should be based on an average that you can set yourself (ie last 500 miles) - that'd give you control over its relevance to your future driving.

David Trushin | February 16, 2013

All this points out that we should have the capability to change what we see on the instrument panel to what we want to see and can use the best in our individual circumstances. On my ICE, I use instantaneous mph to help modify my driving habits to get the most mileage. I could use the Wh/mile, but unfortunately the font size is too small for my myopic eyes. User configurability please.

Another vote from me to leave Rated Range in place...In decent weather (Mid 40-ish degrees and above), it's been very near spot-on with my actual miles driven. I'll take that any day, and modify in my head if the weather turns extreme, if I'm hauling a ton of cargo, or if I feel like driving like a lunatic :p

sergiyz | February 16, 2013

I'd leave it as is and add an option in the energy app to average over lifetime.
The more you drive the more accurate it will be.

patp | February 16, 2013

Can't agree more for cold temperature. Rated is useless and dangerous:

The Consumer Reports article conclude with:

"One additional takeaway: Perhaps it's the "projected range" that needs to display more prominently than the "rated range."

DT;
The dash is too far away for your myopia? I hope you drive with distance focus glasses. Unless you go the classic Texas oil baron route, and have the windshield ground to your prescription!

PeterV | February 16, 2013

Seasonal variations are so important in determining range. I agree with those who promote a prominent display for projected range based on the past 500 miles!!!!! This would keep reporters out of trouble.

mallynb | February 16, 2013

There are too many variables that are unknown for either range estimate to be accurate. Speed, traffic, driving habits, wind, hills, passenger load, heater or AC on/off, etc., etc. The assumptions for either range calculation can't account for any of these in advance. Other information, such as miles per minute of charge, aren't any more reliable. Our Model S hasn't been delivered yet. I hope I will be able to display a simple equivalent to our ICE's gas gauge. When the battery capacity gets below a quarter full, I'll look for one of the charging stations that I've located along our preplanned route.

Brian H | February 16, 2013

PeterV | February 16, 2013
.
Seasonal variations are so important in determining range. I agree with those who promote a prominent display for projected range based on the past 500 miles!!!!! This would keep reporters out of trouble.

Not if they're either looking or working to produce it.

TonyF | February 16, 2013

I find rated range to be the best for me. If the weather is really cold, really hot, or if I am in stop and go traffic, I have learned to estimate a certain percentage of rated range to give me a good estimate of how far I will actually be able to go. In moderate weather and on the highway, I still like rated because I know I can approach it and often exceed it (I did it this winter in the Philly area and it was only 40-deg). Additionally, when we are far from our home base or another charging station and rated miles remaining is pretty close to actual miles remaining, all we have to do is slow down and we will make it to our destination. To me, rated range is more valuable than projected range. And ideal range is the least valuable.

GLO | February 16, 2013

We've found rated range to be spot on. We are in CA so the climate is kind to the battery. I think there are too many variables to get rid of either. My not-so-sage advice is to see what works with your driving style and location and learn to use that...IMHO

robkal007 | February 16, 2013

Rated range doesn't seem to corollate very well when I am just driving around town mindlessly, but on the road driving for efficiency it is spot on. Driving LA to San Francisco yesterday at 65 - 70 mph with gentle acceleration and minimal braking it was less than 5% off on all four legs between Superchargers. I'm confident enough now to make the 111 miles from Harris Ranch to Gilroy with only 20 extra rated miles. What would be very helpful is a way to display the difference between rated range and remaining distance on the Google map readout for a trip which would be "rated reserve." I keep doing that calculation mentally and adjust my driving style accordingly.

tezco | February 16, 2013

I'd prefer a good SOC reading over rated or ideal since neither matches my driving.

Sudre_ | February 16, 2013

I just did my first 180ish mile round trip and I like the rated range. It was a mix of highway, city and country side roads. The rated range was spot on.

robkal007 is right tho. Heavy city driving rated is not the best. In the city tho I don't worry about my range at all. It's the long distance drives I need that accurate number and rated works good for that.

TeslaLABlue | February 16, 2013

@ Sudre

I also like rated range... I drove all day all over Los Angeles freeways and surface streets and the rated range was perfect.... the miles I drove correspond exactly to the rated range used on the battery.

eltonf | February 17, 2013

Rated range is great for locations with mild weather like California. For most other places they should use projected miles using the driving pattern over the last few minutes. At minimum show both or make it an easy toggle option.

The number of minutes used to calculate projected miles can be higher when the battery is full, like over the last 30 minutes. As the battery depletes the projected miles should be calculated over a shorter period. If less than 15% range remains then projected miles should be calculated every 5 minutes since minor changes in driving behavior make a huge difference.